Nick Hunn, from Bluetooth chip maker TDK, said there were probably better ways of getting data from a phone.
If you wanted information from someone's handset you would probably try and nick it rather than do it electronically," he said.
If you pinch someone's handset, then your victim will realise that a crime has been comitted, the fuzz will be after you, and when they finger your collar you'll have the evidence on you. You're nicked!
Whereas if you do it by bypassing the bluetooth security, your victim won't realise, and you won't get caught. You can sit with a laptop nearby and suck data to your heart's content all day, and it seems unlikely that anyone will twig that a crime happened, let alone know who dunnit.
Heck, you can even script your data harvester so that it steals from several people in parallel. Which won't get noticed, unlike a pickpocket with more than 2 arms.